Recently, as next-generation nonvolatile semiconductor memories, resistive random access memories have been attracting attention, such as a magnetoresistive RAM (MRAM) in which a magnetoresistive effect element serves as a memory element, a resistive RAM (ReRAM) in which a variable resistive element serves as a memory element, and a phase change RAM (PCRAM) in which a phase change element serves as a memory element.
As an example of the application of the resistance change type memory, the use of this memory as an alternative memory to a DRAM is expected.
According to the specification of double data rate (DDR) DRAM, a capacitor having a large capacitance is formed in a DRAM chip to stabilize the operation of the DRAM chip. Since a memory cell of the DRAM includes a capacitor (e.g., a trench capacitor), the capacitor having the large capacitance for stabilized operation can be relatively easily formed in the chip.
However, in the resistance change type memory which is driven in accordance with the operation standard of the DRAM, the capacitor having the large capacitance has to be formed in the same chip as the memory cell by adding a formation step separate from the formation step of the memory cell.